LysKOM Protocol A

This page is devoted to the LysKOM Protocol A protocol. LysKOM is a conferencing system developed by the Lysator Academic Computer Society at University of Linköping. Several introductory texts in Swedish are available.

LysKOM can be seen as a cross between news and email, but with the presence and speed of IRC or ICQ. LysKOM is suitable for small or medium-sized communities. The largest known LysKOM server installation is used by slightly less than 1000 users each month, and typically has 300-500 simultaneous users.

LysKOM Protocol A is a protocol that runs on top of TCP/IP. It has been in use at Lysator since 1990, and has proven to be extensible in a backwards-compatible way. (Clients from dating from 1990 can still communicate with a modern server.) Since the start, it has used port 4894. That port was registered by IANA on 2001-06-20.

The LysKOM server and several clients are available for download from ftp://ftp.lysator.liu.se/pub/lyskom/ and http://www.lysator.liu.se/lyskom/.

Protocol specification

The protocol specification is available in several formats:

The Texinfo source code. All other formats are generated from this source. (This document makes heavy use of Texinfo macros. Due to bugs in all current versions of texinfo.tex it cannot easily be typeset as DVI or PDF. Get the source code for lyskomd for an ugly workaround.)
Info files, as a gzipped tar archive.
Browsable HTML.
Single-file HTML. This is a single large HTML file.
PDF. This file contains several typos. The HTML- and info versions should be trusted more than this file.
DVI. This file contains several typos. The HTML- and info versions should be trusted more than this file.
Machine-readable summary.

protocol-a-full.txt

The full Protocol A specification, with stable names.

protocol-a-recommended.txt

The recommended requests and asynchronous messages, and all types they need, with stable names.

protocol-a-current.txt

The recommended requests and asynchronous messages, with the names used in version 11.1 of the specification.

Older versions

For reference purposes, older versions are kept online.

Edition	Release date	Texinfo	Info	Online		PDF	DVI	Machine readable
11.1	2003-08-30	Texinfo	Info	Browsable HTML	Single-file HTML	PDF	DVI	full	rec	current
11.0	2003-08-24	Texinfo	Info	Browsable HTML	Single-file HTML	PDF	DVI	(added in 11.1)
10.7	2002-11-03	Texinfo	Info	Browsable HTML	Single-file HTML	PDF	DVI	(added in 11.1)

For even older versions, you have to check the server sources.